Article History
Received: 25 May 2018
Accepted: 10 October 2018
First Online: 10 January 2019
Ethics approval and consent to participate
: The establishment of this database was approved by the Massachusetts Institute of Technology (Cambridge, MA) and Beth Israel Deaconess Medical Center (Boston, MA) and consent was obtained for the original data collection. Therefore, the ethical approval statement and the need for informed consent were waived for this manuscript.
: Not applicable.
: The authors declare that they have no competing interests.
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